Thermal performance of over-ground household biogas production system heated by solar energy

doi:10.11975/j.issn.1002-6819.2015.15.027

	Thermal performance of over-ground household biogas production system heated by solar energy
	Feng, Rong; Li, Jinping; Li, Xiuzhen; Yang, Jieyuan
刊名	Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
	2015-08-01
卷号	31 期号:15 页码:196-200
关键词	Biogas Collector efficiency Electron tubes Flow of water Heat losses Heat pipes Heat transfer coefficients Heating Rural areas Solar energy Solar radiation Solar water heaters Temperature Water Water heaters Collecting efficiency Design optimization Household biogas Inlet water temperatures Lanzhou University of Technology Renewable energies Temperature controllers Thermal Performance
ISSN号	10026819
DOI	10.11975/j.issn.1002-6819.2015.15.027
英文摘要	Household biogas is widely used in rural areas of China because it is clean, convenient and renewable energy, and the temperature of slurry in biogas digester is one of the most important factors on the biogas production. It has been proved that heating the biogas digester by solar energy is an effective manner to improve the biogas production performance of digester in winter, and many scholars have researched the thermal performance of heating the biogas digester by solar energy. The new type over-ground household biogas digester has been researched and developed successfully by Lanzhou University of Technology, which can be applied in most areas of China. In this paper, the thermal performance of the new type household biogas production system was experimentally studied in order to provide guidance for the design optimization and promotion of this type of system, which mainly included the heat collection efficiency of vacuum-tube solar water heater, the heat loss of digester and the heat transfer coefficient between hot water and slurry. The new type of system had been constructed completely in November, 2014 in a farmer family in a village of Minqin County, Gansu Province, including an vacuum-tube solar water heater with 3.85 m2 heat-collecting area which consisted of 40 vacuum tubes made of glass, an insulating room of 1.9 m × 1.9 m × 2.6 m, a rheid biogas digester of 1.6 m × 1.6 m × 2.5 m, a temperature controller, a circulating pump and other devices. After feeding 1.73 m3 slurry to the digester, the test had been done from December 1st to December 22nd, 2014, and the following parameters were measured: solar radiation on the collection face of solar water heater, hot water temperature in solar water heater's storage, ambient temperature, slurry temperature in digester, inlet and outlet temperature of heat pipe and hot water flow rate in heat pipe, which were recorded by the computer automatically. Else, in order to avoid reducing the activity of methane bacteria caused by the temperature's quick rise, the daily temperature rising was controlled within 2. Five days later, the slurry temperature reached up the designed value, and then was kept at (27±2) when the lowest daily ambient temperature was within -9--18.2, and the average daily ambient temperature was within -2.1--8.6. The results showed that, if the solar radiation on the collect area of solar water heater increased by 1 MJ/m2, the daily average heat-collecting efficiency would increase by 5.99%; if the average daily temperature difference of hot water and ambient increased by 1, the efficiency would reduce by 1.5%; if the average daily temperature difference of slurry and ambient increased by 1, the daily heat loss of digester would increase by 0.931 MJ; if the inlet water temperature increased by 1, the heat transfer coefficient between hot water and slurry would reduce by 0.11 W/(m2·K); the slurry temperature had significant effect on the heat transfer coefficient, and when the slurry temperature increased by 1, the heat transfer coefficient would increase by 0.83 W/(m2·K). ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
语种	中文
出版者	Chinese Society of Agricultural Engineering
内容类型	期刊论文
源URL	[http://ir.lut.edu.cn/handle/2XXMBERH/112365]
专题	能源与动力工程学院
作者单位	Western China Energy & Environment Research Center, Lanzhou University of Technology, Lanzhou; 730050, China
推荐引用方式 GB/T 7714	Feng, Rong,Li, Jinping,Li, Xiuzhen,et al. Thermal performance of over-ground household biogas production system heated by solar energy[J]. Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering,2015,31(15):196-200.
APA	Feng, Rong,Li, Jinping,Li, Xiuzhen,&Yang, Jieyuan.(2015).Thermal performance of over-ground household biogas production system heated by solar energy.Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering,31(15),196-200.
MLA	Feng, Rong,et al."Thermal performance of over-ground household biogas production system heated by solar energy".Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering 31.15(2015):196-200.